This invention relates to transmission devices having a rotary input shaft and oscillating output shaft, including a device to change the angle of oscillation, such as used in rotary sprinkler heads for irrigation where water causes the sprinkler to rotate in order to provide water precipitation over a desired area.
Oscillating transmission devices for rotatable sprinklers have been known in the prior art for use in irrigation. Patents setting forth a background for this invention are: U.S. Pat. Nos. 3,038,666; 3,107,056; 3,645,451; 3,713,584; 3,724,757; 3,854,664; 4,272,024; 4,353,507; 4,568,024; 4,624,412; 4,625,914; 4,634,052; 3,383,047; 3,526,363; and 5,115,977.
Patent application Ser. No. 932,470, filed Nov. 18, 1986, now U.S. Pat. No. 5,417,370, for xe2x80x9cA TRANSMISSION DEVICE HAVING AN ADJUSTABLE OSCILLATING OUTPUTxe2x80x9d; patent application Ser. No. 037,704, filed Apr. 13, 1987, now U.S. Pat. No. 4,867,378, for a xe2x80x9cSPRINKLER DEVICExe2x80x9d; patent application Ser. No. 183,071, filed Apr. 19, 1988, now U.S. Pat. No. 4,901,924, for a xe2x80x9cSPRINKLER DEVICE WITH ANGULAR CONTROLxe2x80x9d; patent application Ser. No. 245,126, now U.S. Pat. No. 4,955,542, for a xe2x80x9cREVERSING TRANSMISSION FOR OSCILLATING SPRINKLERSxe2x80x9d; and patent application Serial No. 626,993, filed Dec. 13, 1990, now U.S. Pat. No. 5,148,991, for a xe2x80x9cGEAR DRIVEN TRANSMISSION FOR OSCILLATING SPRINKLERxe2x80x9d, all filed by Carl L. C. Kah, Jr., are related to this divisional application of patent application Ser. No. 08/269,342.
Patent application Ser. No. 932,470, now U.S. Pat. No. 5,417,370, discusses the need to maintain a continuous bias on the reversing transmission""s gear cage which alternately shifts a pair of terminal gears carried on a gear cage assembly into and out of engagement with an output shaft ring gear during the period that a reversing toggle is being moved over its reversing overcenter position. Maintaining a bias on the driving terminal gear insures that it will not become disengaged during stopping or starting of the drive when the reversing toggle bias has been lifted off.
Also disclosed was a reversing gear drive configuration in which the driving pinion was always engaging the output gear with the reaction force on the driving terminal pinion gear tending to hold the driving gears in engagement with the driving input gear during driving in either direction and input shaft torque is not applied to the shiftable gear cage in a manner to cause the gear cage to be disengaged in either of its driving engagement positions.
In my U.S. Pat. No. 5,148,991, issued Sep. 22, 1992, several oscillating sprinkler drive configurations are shown having a shiftable gear cage bias means for continuously biasing the gear cage towards one driving engagement direction or the other up to the moment the gear cage is shifted overcenter.
An object of this invention is to have a transmission for alternately driving an output gear to oscillate it, by one driving gear and then another, with spring means being provided to prevent the transmission from being placed in an xe2x80x9coffxe2x80x9d position with neither driving gear positioned to drive the output gear upon starting.
Another object of this invention is to have an oscillating transmission with a pivoted gear cage having two drive gears, a first clockwise drive gear and a second counter-clockwise drive gear, for alternate driving engagement with an output gear to oscillate it, a first and second overcenter spring means act on said gear cage in one direction to place one drive gear into driving engagement within said output gear while placing said other drive gear out of driving engagement. To reverse the position of the drive gears, the first spring means has its biasing force removed from the gear cage to be placed in an overcenter position to bias the gear cage in the opposite direction so that the other drive gear can be placed in driving engagement with said output gear and the one drive gear can be placed out of driving engagement, said second spring means retaining the one drive gear in driving engagement until the first spring means is biasing the gear cage to the reverse posit;on and has overcome the second spring means to place it in an overcenter position; the second spring means thus acts together with the first spring means to pivot said gear cage to its reverse position. The second overcenter spring means insures that during the time that the pivoted gear cage is not being biased by the first overcenter spring means that it remains in one driving position or the other, and cannot be left in a xe2x80x9cdead-centerxe2x80x9d position where neither of the two drive gears is in driving engagement with said output gear.
A further object of this invention is to provide an oscillating transmission which has an angular positioning member for directly setting the oscillating angle and a shaft with an adjusting, or setting, slot accessible on the top of an oscillating output cap. The slot has an arrowhead at one end indicating the position of an adjustable reversing actuator within the transmission, and an arrowhead is placed on the top of the output cap indicating the position of a fixed reversing actuator within the transmission. Indicia representing angles can be placed around the output cap to aid in positioning the setting slot at a desired angle. The ability to look at the adjustable angular selection dial and see at a glance what arc a particular unit is set for, provides an enhanced marketability for products using this drive, especially in the sprinkler field. When used as a sprinkler device, the sprinkler devices can be removed from a lawn location for cleaning or inspection and when it is desired to reinstall the sprinkler device, the desired angle of oscillation can easily be set by simply looking at the top of the device and if it is not already properly set, a rotatable member can be pointed at the desired angle position indicated on the top of the sprinkler device.
Another object of this invention is to provide for a driving connection between a rotating input shaft and an output gear for oscillating the output gear and providing for changing the angle of oscillation. The output gear has a fixed projection thereon to reverse rotation at one side of the angle and a cylindrical member mounted for rotation with said output gear has an adjustable projection to reverse rotation at the other side of this angle, relative rotation of said cylindrical member with said output gear changing said angle of oscillation.
A further object of this invention is to provide an oscillating transmission having a ring gear mounted for rotation with means for oscillating said ring gear; a toggle means reverses the rotation of said ring gear from one direction to the other, with contact means rotated by said ring gear engaging said toggle means to reverse rotation from one direction to the other, said contact means are two projecting members, with means mounting said two projecting members for relative movement to vary the angle at which said toggle means is actuated, said one projecting member being mounted on said ring gear while said other projecting member is mounted for rotation within said ring gear. Means connect said other projecting member to said ring gear for being driven thereby to contact said toggle means to reverse rotation of said ring gear, and means disconnect said other projecting member from said ring gear when said other projecting member is rotated to vary the angle between the projecting members.
An object of this invention is to provide a transmission having an oscillating output ring gear with a hollow shaft at the center thereof, said oscillating hollow shaft providing the output of the transmission such as by a gear attached thereto, a cylindrical member being mounted for rotation with said hollow shaft, an adjustable projection extending from said cylindrical member to serrations on the interior of said ring gear for contacting an actuating means to reverse transmission direction, said serrations connecting said adjustable projection to said ring gear for being driven thereby, said serrations providing for relative movement when said cylindrical member is rotated to vary the angle of rotation; said cylindrical member can be rotated directly through the hollow shaft.
Another object of this invention is to provide a torque-limiting member between said cylindrical member and said hollow shaft for providing for rotation of said cylindrical member without placing undue forces on any other operating parts.
Another object of this invention is to provide an oscillating transmission having an oscillating ring gear with a hollow shaft at the center thereof, said oscillating hollow shaft providing the output of the transmission, a nozzle head oscillated by said ring gear for receiving a flow of water through said transmission.
A further object of this invention is to provide an improved oscillating drive having a reversing gear cage and toggle device mounted on a base member for oscillation, said gear cage having two spaced driving gears always engaging an output gear with one spaced driving gear having an idler gear, either driving gear is driven by a spur gear on an input shaft located in the space between one driving gear and idler gear to drive the output gear, said input shaft extending through said space from said base member with a sleeve therearound with said gear cage having an elongated opening around said sleeve, the length of the elongated opening determining the engagement of the teeth of the spur gear with its cooperating driving gear or idler gear to prevent excessive or unnecessary interaction between the gears.
Another object of this invention is to provide an improved oscillating drive having a reversing gear cage wherein said gear cage is alternately biased by first biasing means in one or the other of two driving positions to provide for oscillating movement, second means being provided for biasing said gear cage in one of said directions to maintain a driving engagement when said first biasing means has been removed.
A further object of this invention is to provide an improved oscillating drive having a reversing gear cage with two spaced driving gears always engaging an output gear; either driving gear is driven by an input shaft, located in the space between the driving gears, to drive the output gear; the reaction force on the driving gear tends to hold the reversing gear cage and driving gear into engagement with the input shaft.
Another object of this invention is to provide an improved oscillating drive having a toggle device mounted on a base member for oscillation, stops are provided between said toggle device and base member for (1) limiting the biasing load on gears during operation; and (2) providing ease of spring insertion during assembly.
A further object of the invention is to apply the important concept of continuous gear cage engaging bias toward driving engagement for reversing transmissions used in oscillating sprinkler drives to ensure proper operation under all conditions of operation, setting, handling, and installation.
Another object of the invention is to provide a simplified shiftable pinion gear configurations in which, the shiftable gear cage which now is only a shiftable gear carrier for a single driving pinion gear and which remains in constant engagement with the output ring gear is shifted about the output ring gear center to engage one or the other of two counter rotating input shafts to achieve the reverse driving action. An overcenter driving engaging bias is provided which will insure the proper driving position of the driving pinion carrier until shifted to its reversed position by a shifting arm which has a lost motion connection to allow the shifting arm to be moved over it""s overcenter biasing spring position before it engages the carrier to shift it out of driving engagement and carry it over its center so that the gear cage carrier""s overcenter bias can then be applied in the reversed direction to carry the gear cage (carrier) into its full driving position in a reversed driving direction and maintain the driving pinion gear in proper reverse driving position until again shifted to provide driving engagement in the opposite direction.
Another transmission configuration is also shown where the reversing toggle""s overcenter bias is a single spring and is also used to directly bias the gear cage assembly in its driving position in either direction. At the bias spring neutral center position of the reversing toggle, any gear cage movement towards premature disengagement of the driving terminal gear changes the overcenter relationship of the single overcenter reversing biasing spring, (acting on the single driving pinion gear cage (carrier)) to reverse the direction of its engaging bias and causes the driving pinion gear cage (carrier) to be shifted to its reversed driving position causing the desired reversing action while maintaining the driving engaging bias up to the moment of the reversing action occurring and then reapplying it in the reversed direction.
A third transmission configuration is shown where the overcenter carry action of a shifting arm is provided by the deflection of a spring member which carries the driving pinion gear cage (carrier) member overcenter once it has been driven out of driving engagement by the action of one of the arc control contact members being driven against the spring member shifting arm.
Because of the need to minimize the outside diameter of the gear drive assembly to reduce the sprinklers housing size and pressure surface and the central flow area needed to get water to the sprinklers oscillating nozzle a very compact and simple reversing gear arrangement is needed. Also the sprinkler mechanism needs to operate reliably for a long period of time in a very harsh environment of dirt and dirty water with no corrective attention. It is an object of this invention to provide improved and simplified reversing drive means for oscillation nozzle sprinklers for high reliability and more liberal manufacturing tolerances and ease of reliable product assembly.
Another object of this invention is to provide an improved oscillating drive reversing gear mechanism with two oppositely rotating input shafts spaced apart with a shiftable gear carrier (cage) for a single driving pinion gear which is shifted between engagement with one or the other of the counter rotating input shafts and the output drive gear to achieve the reversing drive of the output shaft. The reaction force of the driving gear on the driving pinion gear and shiftable gear cage carrier tends to hold the reversing gear cage and driving gear into engagement with the input gear in either of its driving positions.
Another object of the invention is to provide a reliable, simplified oscillation sprinkler transmission where the reversing gearing may be replaced by a friction rubber wheel drive to provide a friction driving connection between the input shaft and the output drive means. This can also provide the clutching action to prevent damage to the gear drive if the nozzle and output shaft is force rotated. The manufacturing tolerances would also be much less restrictive for a friction drive than a pure reversing gear drive and have substantially fewer parts than the slip clutch to output shaft arrangement described and shown for the pure gear drive. These features are a further object of the invention.